Multiple GUI's listening on the same UDP port

Hi,

I am writing some matlab GUI's which use UDP via the instrument control toolbox to list for data. However, I find that only one GUI seems to able to connect to the port at a time.

e.g. I have server process that's generating UDP datagrams on the local host at port 50009. Each of my GUI's tries to set up a UDP connection to "localhost" and 50009 as the "LocalPort". But only the first one makes the connection - the others give an error "port already in use".

I'm not very experienced with UDP, so perhaps there is something obvious I am doing wrong, but I can't see what it might be.

I'm using MATLAB 2011a with the instrument control toolbox on Windows XP.

Thanks in advance, Paul